1. Field of the Invention
The present invention relates to an inkjet printing apparatus and a method for controlling an inkjet printing apparatus.
2. Description of the Related Art
In inkjet printing apparatuses, ink is sometimes deposited to the surface of a print head (hereinafter also referred to as an “orifice face”) having nozzles (ejection ports) formed therein and, therefore, normal ejection is interfered. In printing apparatuses that form an image using a plurality of types of ink that react to one another or in printing apparatuses that forms an image using reaction liquid and ink, the ink may be firmly deposited onto an orifice face, and it may be difficult to remove the deposited ink. In addition, in printing apparatuses that solidifies ink using an ultraviolet ray, a microwave, or heat in order to improve the fastness of the ink, the same issue arises. To address such an issue, a solvent inkjet printer or a UV-curable inkjet printer is sometimes used. In some cases, such a printer requires a maintenance operation performed by a user.
Examples of the maintenance method include (1) wiping away ink by sliding a wiper or a blade on an ejection surface and (2) absorbing ink by urging a porous sheet-like purge member having ink absorbency against an ejection surface. The sheet-like purge member is also referred to as a “web”. Hereinafter, the sheet-like purge member is simply referred to as a “sheet member”. The above method (2) is described in Japanese Patent Laid-Open No. 2003-300329. In the technology described in Japanese Patent Laid-Open No. 2003-300329, after the purge operation is performed, a predetermined amount of the sheet member is wound and collected.
According to the above-described method (2), accumulated ink and dust particles deposited on the orifice face can be removed. If a recording medium is paper, a paper fiber that generates an undesired ink line on the recording medium can be also removed. According to the above-described method (1), if a wiper is used, wet ink spreads after the ejection surface is wiped. In contrast, if a wiping mechanism is used, wiping of thickening ink generated by heat and evaporation may be difficult. The method (2) can address such issues. Accordingly, the ink ejection performance can be more consistently maintained or recovered.
If the orifice face of the print head is cleaned using the method (2), that is, by using a sheet member, the following issue arises: if the amount of winding is set to a small value, the entire portion of the sheet member used is not collected, in some cases. Accordingly, the portion of the sheet member used for cleaning the orifice face may be reused in the next cleaning operation and, thus, the cleaning effect may be decreased. In contrast, if the amount of winding is set to a large value, the portion of the sheet member used can be more reliably collected. However, it is likely to collect an unused portion. In addition, since the use amount of the sheet member increases, the use efficiency of the sheet member is decreased.